Self-rescue equipment is used in harsh environments, such as mines, tunnels, and other enclosed spaces where air can become contaminated, toxic, or oxygen deficient atmospheres, for example upon explosion, fire or other event. Workers must avoid breathing the contaminated air during their escape from the environment. Self-rescue equipment is designed to withstand the daily rigors of harsh environments and perform reliably as needed, for example in emergency situations to facilitate escape from the immediately dangerous to life or health (IDLH) environment.
A Self-Contained Self-Rescuer (SCSR) is a portable device that provides breathable air while isolating the wearer's respiratory tract from contaminated or IDLH atmospheres. The SCSR is typically carried, worn or located nearby to a worker providing immediate access to respiratory protection with an oxygen source during the worker's daily tasks. The SCSR provides protection for a limited period of time. Government regulations require coal miners, for example, to have immediate access to an SCSR device that provides respiratory protection for at least 1 hour. The SCSR device provides protection that is generally long enough for a worker to travel and access an additional cache stored at strategic location to facilitate escape in emergencies.
As the respirable gas of the SCSR is depleted, the device is exchanged for another device such as a SCBA (Self-Contained Breathing Apparatus) or another SCSR from a cache positioned along the escape route. The worker will need to doff and re-don the next device in order to receive the fresh supply of respirable gas. Doffing and re-donning requires the worker to hold their breath during the exchange and leaves the worker at risk for exposure to the dangerous atmosphere.